keyser



J. J. KEYSER Dec. 15, 1959 DOUBLE-BELT DRAWING UNIT FOR SPINNINGMACHINES 3 Sheets-Sheet 1 Filed July 29, 1957 Fig. 2

Fig. l

lNVENTOR Taba.nn Jieob a e/J A-w/ g .J. J. KEYSER Dec. 15, 1959DOUBLE-BELT DRAWING UNIT FOR SPINNING MACHINES Filed July 29, 1957 3Sheets-Sheet 2 INVENTO F? aann 3340197 6 J. J. KEYSER Dec. 15, 1959DOUBLE-BELT DRAWING UNIT FOR SPINNING MACHINES Filed July 29, 1957 3Sheets-Sheet 3 //v VENTOI? J2me b fyftr Pale United States Patent Thepresent invention relates to improvements in apron drafting roller unitsfor spinning machines, particularly for slubbing and finespinningmachines.

It is well-known in the art of spinning that a fiber strand may besubjectedto an adequatebacking within the drafting unit if it ispassedbetweentvvo endless revolving aprons, as is done, for example, ina Casablanca drafting frame of aknown design.

However, all of the known apron drafting units have the disadvantagethat such retaining action is not uniformly exertedfuponall ofthefiberswithin the cross-sectional area of-a fiber strand. This is due to thefactthat Although each of these two different trends of development led.to certain advantages, both of them had certain disadvantages. Eventhough no efforts have been spared in the past to overcome thesedisadvantages, these efforts have sofar been unsuccessful.

. It is the principal object of the present invention to provide asuitable apparatus which while combining the above mentioned twodifferent principles and-advantages inherent thereto, will completelyovercome their individual disadvantages.

According to the present inventiomthis object has been materialized byproviding the lower and/or the upper guide rollers of the belts with atleast one recess within the area of travel of the fiber strand. Theserecesses may be provided in the guide rollers in alternate succession ofthe latter, and either in'the guide rollers for only one apron or in theassociated rollers of both aprons. They may also be providedin someofthe associated rollers of both aprons, while in-others they maybeentirely omitted.

Another feature of the invention consists in making the distance, thenumber, and/ or the weight of the guide rollersof each-drafting unitadjustable. All of the guide the fibers directly engaging with the twoaprons are retained to a greater extent than those disposed at the inside of the beltsfandthat the inner fibers mightstart to float when theother fibers while being drafted are pulled out of the fiber. strand.This disadvantage becomes noticeable particularly if the floating fibersare considerably fabric will result. p

Many efforts have been made in the past to overcome shorter than theaverage staple so that an uneven yarn or these disadvantages of theknown apron drafting units. These efforts progressed primarily in twodifferen t dixfections which tosome extent were opposed to each otherand which maybe described as follows: f

(a) The drafting aprons are'exposed to considerable wear, the extent ofwhich depends upon the material of which they are made, the type andquantity of the fibrous material being processed, and the pressure atwhich the aprons act upon each other and upon-the fiber strand betweenthem. With three-roller draftingunits with double aprons it has,therefore, been tried to provide theguide rollers of the apronsunderneath the path for the-fiber strand with a recess. This allows theaprons to form passages betweenithe pressurepoints which 'also permitlonger fibers to be drafted properly without the danger that such fibersmight break; This also increases the elasticyieldability"oftheaprons,while reducing the wear of the aprons. Also a softer retainingaction will be obtained which, however, is less than that produced bysmooth rollers without such recess. A 5

(b) Independently of this procedure to protecting the material of theaprons, various attempts-have been rhade to improve the-retainingaction, that is, to equalizeand increase such action, by passing thefibers through the drafting field not in" a straight direction but alonga curved path so that the frictional retainingaction onthefapron thefibers 'inside the fiber strand. This is brought about will be increasedby the looping angle thus formed.

Even the very first Casablanca drawing frame'provided for suchdeflection of the aprons and the path of travel of the .fibers. However,such a rigid defiecti o hbf the aprons between rollers involvedconsiderable difilculties in that the aprons could not be made to runquietly, and that the repeated deflection between rigid rollers easilyincreased the retaining action to such an extent asto lead to a breakingof the fibers and, that last but not least; the aprons were WOl'l'litOaagraterextent than was warranted by suchincreased retainingraetion'. ii

rollers of one drafting unit may also be made either of thesame weightorof different Weights. --By means of the present inventon it ispossible to attain advantages which previously were unattainable eitherin the manufacture of spinning "machines or in their operation any ofthe numerous branches: of thespinning n; i: i a

The present "invention permits a uniform manufacture of the individualparts of a drafting unit which will'be applicable in place of all othertypes of drafting units previously used and thus a universal applicationof such units to all types of fibers in the various branches ofspinningfl p i In a view of the. great adaptability and operationalflexibility: of the drafting unit according to the inventionawhich isdueto the adjustability of the distance between the guide rollers and thepossibility of applying guide rollers eitherwith or without recesses,depending upon the type of fibrous material to be proc-' essed, thedrafting'unit according to the invention may be" applied withoutdifiiculty either for processing long staple fibers, for example,worsted, or-short staple fibers,

for example, East Indian cotton. This is due to the fact that, inaccordance with the larger or smaller disguided in such a mannerduringthe drafting of the individual=fibers that the short staple fiberswill be prevented fiorh floating which considerably affects the qualityof the spuniyarn. As a matter of fact, a floating of fibers in adrafting unit designed and properly adjusted according to the inventionwill be absolutely prevented since nolonger only the fibers directlyengaged bythe aprons are subjected to a proper retaining action but alsoby the undulated back and forth movement of the fiber strand is. whendue to this movement the crosssectional shape of the fiber strand isbeing changed between'two points ofpassage throughthe guide rollerswhich are provided with an upper or lower recess, respectively. In thisway, it is also possible to exert a better retaining action upon shortfibers than was previously attainable so' that the quality of the 'yarnwill also be improved.

These and other advantages may be realiz ed particularly and in the mostsimple manner in wide-apron drafting units, that is, in units havingrevolving aprons which extend over several spinning stations and possibly fromroller stand to roller stand. Such advantages could'not beattained by the use of wide-ribbon drafting units offprevious design. a

These and further objects, features, and advantages of the presentinvention will now be described in detail with reference to theaccompanying drawings, in which- Fig. 1 illustrates a section of adrafting unit with a recessed guide roller according to the prior art;

Fig. 2 shows a diagrammatic side view of a part of a drafting unitaccording to the prior art, in which the material is drafted along acurved path;

Fig. 3 shows a partial perspective view of the guide rollers accordingto the present invention for use with a double apron;

Pig. 4 illustrates a cross section of a double-apron drafting unitaccording to the invention;

Fig. 5 illustrates a cross section of the same drafting unit as shown inFig. 4, but with the pairs of cooperating guide rollers spaceddifferently from each other;

Fig. 6 shows a cross section of the same drafting unit as in Figs. 4 and5.but a different arrangement of the rollers of each pairs of guiderollers; while Fig. 7 illustrates an arrangement which differs from thatof Fig. 4 in that two grooved end rollers (directly preceding thedelivery rollers not shown) are employed instead of one only.

Referring to the drawings inwhich similar parts are designated by thesame reference numerals, Fig. 1 illustrates a grooved apron guidingroller as used prior to the invention. The lower guide roller 1 has arecess; or groove into which the belt can deflect, while the fiberstrand passes through thedrafting area formed between the upper andlower aprons by means of the upper and lower guide rollers. v

' Fig. 2' shows the heretofore known manner of mount elastic flexibilityand the deflection of the aprons, and no longer, as in the conventionaldrafting frames, by the amount of pressure of the upper apron upon thelower apron, that is, by the weight of the individual upper rollers, onespinning point can no longer be influenced by an adjacent spinningpoint. When previously several spinning points, particularly more thantwo, were loaded by one upper roller (either with or without an upperapron), and a thicker slubbing or sliver portion was drawn through therollers at one spinning point, the other point at the same upper rollercould be released so that the retaining action upon the fibers was alsoreleased atthispoint. The upper rollers have for this reason in the pastbeen designed for no more than one or two spinning points, and it wastherefore necessary also in wide-belt drafting'units to mount theseupper rollers in special supports between the normal individual bearingsupports. The present invention renders such intermediate supportsunnecessary. Now, not only the lower guide rollers including the lowerapron may extend from roller stand to roller stand and may be mountedtherein or in common pivotable frames on said roller stands, since thenew manner of guiding the aprons prevents the transmission of anyinfluence from one drawing point to another due to the fact that apossible thicker slubbing or sliver .portion can only produce anincreasing bulging of the apron at this particular spinning point butcannot result in a lifting of the upperroller. Furthering the guiderollers for the upper and lower aprons within the same horizontal plane.This results in a drafting field in which the fiber strand to bedraftedis passed along a'curved path so that the. frictional retain ingforce will ,be-increasedj. Figs. 3 and 4 illustrate the principleaccording to the present invention. Guide rollers 1, 2, 3, and 4 for thelower apron and the corresponding guide rollers 1, 2., 3', .and d forthe upper apron have alternating recesses or grooves at the differentspinning points. These grooves alternate both in .their horizontalsuccession as well as vertically between the associated upper and lowerrollers. vThe width of the grooves substantially corresponds; to theWidth'Of' the grooved rollers so that the transverse. motion of theapron being drawn into the apparatus can be retained in the usual form.For a-better illustration of the invention, the cross section accordingto Fig. 4 and the succeeding figures are taken through the groovedportion of the guide rollers. Fig. .4 illustrates the superimposedaprons as being rigidly sup ported in an alternating succession betweenthe guide rollers only either at the upper or lower side, while at the'respective opposite side they are free and can deflect into therecesses.

By such an arrangement the followingadvantages will be attained:

1) The fibers will be subjected to a very soft elastic retaining actionwhich is caused along the entire drafting length solely by theelasticity of the material of the aprons;

more, it is no longer necessary toapply several upper loadrollers ofdifferent weights in accordance with the material to be processed but,generally speaking, the rollers may all. beof, equal weight since thecontrol of the retaining force will be 'attainedby the number of or thedistance between the guide rollers. Also, any changes in thedimensionstO'WhlCh the apronsmight, be subjected after. acertti'nlength oftimeofoperation, for example, by swelling, and their effect upon thespinning process will be alleviated by the new manner of guiding theaprons.

The location and depth of the recesses within the individual upper orlower guide rollers may be varied in many different ways. Thus, forexample, if desired, the recesses may be entirely omitted in some of theassociated pairs of rollers, for example, in the very first pair ofrollers 1, 1', and they may be provided only in the following pairs.

Such modifications are illustrated in Figs. 5 to 7 in similarcrosssections as shown in Fig. 4.

Fig. 5, shows thelower guide roller 1 adjacent to the spinning roller asWell as the upper guide roller 1' as being without any recesses orgrooves, while the lower guide rollers land 4 and the upper guide roller3' are each provided with a recess or groove. Furthermore,

(2) The aprons andthus also the fiber-strandsare subjected to anundulated, soft deflection so that-'the fibers will be uniformlyembedded within the resilient material of the aprons throughout theentire drafting field;

which means that the retaining action will be entirely,

uniform as well as increased because atthe moment of deflection, i.e.when the fiber strandchanges over, for

example, from the lower to the upper embedding POSi provided withgrooves.

the distances between theindividual guide rollers are made smaller thanthose shown in Fig. 4 so that a drafting unit of this kind may also beused for drafting fiber strands with short staple fibers.

According to Fig. 6, the first guide rollers. 1 and 1' are likewisewithout grooves, while the succeeding lower guide roller 3 and theupperguide rollers 2 and 4' are The distance between the. individualguide-rollers is still less thanin Fig. 5. Furthermore, this, draftingunit includes another non-grooved pair of; guide rollers 6 and 6-whichforms the rear end of the drawingarea so that this arrangement of thedraftingunitwill be suitable for processing short fibers.

Fig. 7 shows an arrangement substantially similar to that of Fig.- 4,except for the fact that the two first guide rollers; 1 and 1' areprovided with grooves. Such roller arrangement is suitable particularlyfor drafting very longstaple fibers, and' it is thus no longer necessaryto provide a special machine which is designed exclusively for draftingsuch long fibers.

Theabove examples also showthat numerous variations in the relativearrangement: of the. guide rollers may be attained by employing guiderollers of different diameters. The distance between the rollers may beadjusted in any convenient manner for instance in the manner shown inU.S. Patent No. 1,644,747 or U.S. Patent No. 2,741,801.

In this manner it is possible to employ a drafting unit of a singlebasic design for various branches of spinning and for all types offibers to be processed inasmuch as it is very simple to adapt thedrafting unit to the respective purpose by merely changing the relativeposition of the guide roller pairs with regard to each other or thenumber of guide roller pairs, and/or the diameter of the guide rollers,since the possibilities of variation are so numerous as to permit anyvariations of such drawing units in accordance with the type of fibersused.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments, but iscapable of numerous modifications within the scope of the ap pendedclaims.

Having thus fully disclosed my invention, what I claim 1. A draftingunit for spinning machines, which includes: an upper apron, a lowerapron for cooperation with said upper apron, and more than two pairs ofmating guide rollers with one guide roller of each pair of guide rollerslocated in said upper apron and the other guide roller of each pairlocated in said lower apron, said pairs of guide rollers being arrangedone behind the other in spaced relationship to each other, each of atleast two successive pairs of said pairs of mating guide rollers beingcomposed of a grooved guide roller in one of said aprons and a matingroller with a continuous cylindrical surface extending over the width ofsaid aprons located in the other apron, the grooves of said groovedrollers being located within the respective apron intermediate the sideedges thereof, the arrangement being such that the grooved rollers ofsaid successive pairs of rollers are alternately located within saidupper apron and said lower apron respectively.

2. A drafting unit for spinning machines, which includes: an upperapron, a lower apron for cooperation with said upper apron, more thantwo pairs of mating guide rollers with one guide roller of each pair ofguide rollers located in said upper apron and the other guide roller ofeach pair located in said lower apron, said pairs of guide rollers beingarranged one behind the other in spaced relationship to each other, eachof at least two successive pairs of said pairs of mating guide rollersbeing composed of a grooved guide rollers in one of said aprons and amating roller with a continuous cylindrical surface extending over thewidth of said aprons located in the other apron, the grooves of saidgrooved rollers being located within the respective apron intermediatethe side edges thereof, the arrangement being such that the groovedrollers of said successive pairs of rollers are alternately locatedWithin said upper apron and said lower apron respectively, and anadditional pair of mating rollers arranged as end rollers of and withinsaid upper and lower aprons respectively, each of the rollers of saidadditional pair of mating rollers being grooved, the grooves of all ofsaid rollers being located at a point within the width of said aprons.

3. A drafting unit for spinning machines, which includes: an upperapron, a lower apron for cooperation with said upper apron, more thantwo pairs of mating guide rollers with one guide roller of each pair ofguide rollers located in said upper apron and the other guide roller ofeach pair located in said lower apron, said pairs of guide rollers beingarranged one behind the other in spaced relationship to each other, eachof at least two successive pairs of said pairs of mating guide rollersbeing composed of a grooved guide roller in one of said aprons and amating roller with a continuous cylindrical surface extending over thewidth of said aprons located in the other apron, the grooves of saidgrooved rollers being located within the respective apron intermediatethe side edges thereof, the arrangement being such that the groovedrollers of said successive pairs of rollers are alternately locatedwithin said upper apron and said lower apron respectively, and anadditional pair of mating rollers arranged as end rollers of and withinsaid upper and lower aprons respectively, each of the rollers of saidadditional pair of mating rollers having a continuous cylindricalsurface extending from one side of said aprons to the opposite sidethereof.

References Cited in the file of this patent UNITED STATES PATENTS1,644,747 Roth Oct. 11 1927 2,255,821 Schlipp et a1 Sept. 16, 1941FOREIGN PATENTS 741,449 Germany Nov. 11, 1943

